The Web of Life (126-8) Savvy


All organisms perceive the world and apply cognitive power to deal with it. That power is considerable and confounding if expecting physical brains to correspond to mental prowess.

There is no single locus in the fly brain for memory formation, yet vinegar flies have apt spatial memory for their environment. Besides a mental 3d map, vinegar flies can remember the sizes, shapes, and colors of objects.

When faced with an uncertain situation, vinegar flies deliberate. Decision-making in flies and humans is selfsame.

The brain is neither the source of awareness nor intelligence. This myth is perpetrated by matterists who refuse to recognize the obvious fact that the consciousness-mind-body complex is energetic in its coherence, and so not subject to material inspection beyond the least interesting bits. The science of life is much more mysterious and intriguingly deep than mere meat and matter.

The multi-layered mammalian cortex is not required for complex cognition. Absolute brain weight is not relevant for mental abilities, either. ~ Turkish psychologist Onur Güntürkün

Brain size is nonindicative of intelligence. Instead of contributing cognitive power, big brains may just provide support for bigger bodies which have more to coordinate and more sensory input to process.

Insects make the point. With tiny brains, insects count and categorize objects; judge the direction and speed of moving objects and respond accordingly. Some, such as houseflies, do so instantaneously. That is a lot of mental processing power on display.


A housefly is hard to swat. The tiny hairs on its body sense air currents, allowing instant response based upon recognized wind direction.

Antennae also detect air changes. In flight, by detecting wind gusts, antennae are used to regulate flight speed.

With 4,000 lenses (ommatidia) in each compound eye, a fly has a constant mental representation of practically everything around it. Its visual range is a couple of meters, which is better than average for an insect.

Like other insects, houseflies have dichromatic color vision. While they do not see the low frequency that represents the color red, flies are able to detect polarization.

Polarization sensitivity helps a fly detect slight changes in light quality. An emerging shadow is readily sensed by polarization change.

While a fly does not get a clear picture, it is especially adept at detecting movement; whence the skittishness of flies.

Sensing a threat while in the air, a housefly can flip itself in the opposite direction within a few wing beats by moving its body in an evasive maneuver while adjusting its flight trajectory. Flies can beat their wings over 300 times per second.

Flies do a precise and fast calculation to avoid a specific threat, and they are doing it using a brain that is as small as a grain of salt. They process information so quickly. Flies’ nervous system and muscles are able to control movements to a very, very fine scale. ~ Dutch biomechanist Florian Muijres

 Fruit Fly Song

Male fruit flies are using information about their sensory environment in real time to shape their song. ~ American molecular biologist Mala Murthy

A male fruit fly courts a female by chasing her. In pursuit, he sings to her by moderating his wing vibrations.

A male adjusts the pitch and tempo of his mating song specifically to the selected female. The faster and farther away she is moving, the louder he sings. Upon catching up, the serenade is softened to a sensitive ballad.

These fly songs have a lot of variability. He measures his distance to the female and uses information about her speed to determine exactly how to pattern his song. ~ Mala Murthy

 Fighting Damselflies

Even animals with simple nervous systems, such as damselflies and other insects, may exhibit complex assessment strategies ~ Brazilian entomologist Rhainer Guillermo-Ferreira

Damselflies, the gracile cousin to dragonflies, have been around for at least 250 million years. In that time they have learned how gauge their prospects.

Male damselflies engage in aerial battles to secure the best territory and mates. Before entering these energy-consuming exercises, they take stock of who they are up against. Damselflies consider various strategies and tactics as they take on challengers of different strengths.

To assess an opponent’s vigor, they first take into account wing size and pigmentation, which indicates power. Strong males tend to overcome weaker opponents through tactics that are less energy-taxing but more aggressive: chasing, grabbing, and biting.

Facing an opponent of equal strength, damselflies limit their odds of injury by going head-to-head in aerial display flights that are longer and more intense. This stamina strategy aims at wearing an opponent down through repeated forays.

In mid-fight, contestants regularly pause to assess the situation and decide whether it is worthwhile to press on.

Threat displays of increasing difficulty intensify when the other shows strain. A bested damselfly withdraws, mentally defeated.

 Mantis Shrimp

It used to be taken for granted that individual recognition was impossible for invertebrate animals. ~ American zoologist Donald Griffin

The 400+ species of mantis shrimp are heavy-hitting predators: marine crustaceans with appendages that serve as clubs or spears (in scientific parlance: smashers and spearers), depending upon species.

To avoid predation, mantis shrimp reside in cavities and burrows in coral reefs. Home is where mating and egg-rearing occur, not to mention a great place from which to stage ambushes.

Prime cavities are worth fighting over, which mantis shrimp do; but mantis shrimp fighting is mostly ritualized gesturing and posturing. Although mantis shrimp could seriously injure each other, they seldom do.

Fighting drains energy. Repetitious battles would be exhausting. Hence the ritualized combat, where the likely victor in a real fight prevails in the mock version.

To top off the adaptation, mantis shrimp can recognize, by chemical cue, other individuals they have encountered. A shrimp avoids the cavity of another that has defeated it, but readily enters the abode of a vanquished foe. Each shrimp earns a reputation.

 Coral Trout

Trout recruit a moray collaborator more often when the situation requires it, and quickly learn to choose the more effective individual collaborator. ~ English zoologist Alexander Vail

Coral trout are a marine piscivore native to the western Pacific Ocean. The live in the open seas and around coral reefs.

Juveniles are fond of prawns. Adults consume a variety of reef fish, with an especial yen for damselfish.

Coral trout do well chasing prey above a reef or in open water but cannot pursue their quarry if it buries itself in a reef crevice.

If a prize looks like it needs to be pried from its hiding place, a coral trout may enlist a local moray eel to aid the quest. Either the eel takes the prey in the reef or scares it back into the open where the trout can pounce.

Coral trout use gestures and signals to flag the location of a prey to an eel, including head shakes and headstands that point the eel in the right direction.

The eel must of course cooperate in the effort. Some are more willing than others, depending upon how hungry an eel is at the moment. Coral trout are as capable of chimpanzees in choosing the right cohort.

A relatively small brain does not stop some fish species from possessing cognitive abilities that compare to or even surpass those of apes. ~ Alexander Vail

 Irukandji Jellyfish

This species is small, less than 2 centimetres across the bell. They’re 96% water. They lack a defined brain or central nervous system. ~ Australian zoologist Robert Courtney

Jellyfish have a gelatinous bell, shaped like an umbrella, trailing tentacles. Jellyfish are the oldest multiple-organ animal, having been in the oceans for 700 million years. There are ~2,000 extant species.

Lacking an identifiable intelligence system, jellyfish have been considered opportunistic grazers. But some are smarter than that.

Irukandji jellyfish do not passively graze. They deliberately fish.

The tiny Irukandji jellyfish is extremely venomous: a single sting of its paralytic toxin can kill a man. Their stingers (cnidocyte clusters) look like a series of evenly spaced bright pearls, running out 1.2 meters. A jellyfish twitches its tentacles as a fishing lure, to attract attention.

They’re targeting and catching fish that are at times as big as they are and are far more complex animals. ~ Robert Courtney

This aggressive mimicry pays off. Larval fish take the bait and are instantly stung. Then they are brought back to the bell and consumed.

It’s a highly successful fishing strategy. ~ Robert Courtney

Irukandji jellyfish fish by day. At night, they contract their tentacles to within 5 cm from their bell, with their cnidocyte clusters bunched up. The jellyfish do this to conserve energy, as their visually oriented prey are less active after dusk.